Neonchameleon
Legend
They made it through all 3 skill encounters and avoided the second combat encounter. We had to stop early since one of the PCs had to go to work. On total we played about 3 hours.
One of the PCs was a little frustrated because he wanted to use ghost sound (Wizard power) during a skill encounter, and I didn't know how to handle that, so I didn't allow it. Did I make a mistake?
"Roll the dice or say yes" - advice in Dogs in the Vineyard. Harder to follow than that sounds

What I'd have done would have been let him use the Ghost Sound to give him a bonus on a normal skill check - either a +2 circumstance bonus for the magical backup or even downgrading the necessary check by one step (from hard to medium or from medium to easy). The ghost sound will help by making the sounds - but skill's needed to time them correctly and pitch them properly. Still, it's a lot better than not having Ghost Sound. And the mistake was only a minor one (I'd acknowledge it, apologise, and move on - it may have been a mistake but only a minor one).
Also don't get caught up with the primary and secondary skills as such. Base it on how the players are pitching the skills, and then decide whether it's primary or secondary and easy, medium, or hard.